{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/85495"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/85495","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Elastomeric Stamping: Design Considerations for Long -Term Maintenance of Neuronal Networks","abstract":"This work describes the development of a technique for high-resolution patterning of proteins or biomolecules on glass substrates for the localization of neurons and their axons and dendrites. The new patterning process uses a microfabricated polydimethylsiloxane (PDMS) stamp with micrometer length features to transfer multiple types of biomolecules to surfaces prepared with (3-aminopropyl)silane (3-APS) or (3-mercaptopropyl)silane (3-MPS) using glutaraldehyde or N-gamma-maleimidobutyryloxysuccinimide ester (sulfo-GMBS) reagents as cross-linkers. PDMS microstamps were used to covalently attach poly-D-lysine (PDL) on glass and silicon dioxide substrates, where polyethylene glycol (PEG) or serine was applied to the background regions. The thickness of each film was measured using ellipsometry and atomic force microscopy (AFM), from which the surface concentrations and grafting density were calculated. Fourier transform infrared spectroscopy was used to examine the structure and organization of the organosilane surfaces. Long-term film stability was evaluated using ellipsometry and static water contact angles. As a biological assay, B104 neuroblastoma cells were plated on microstamped glass coverslips. Results indicated that the stamping and photoresist patterning procedures are equivalent, having an average pattern compliance of 52.6 +/- 4.4% compared to 54.6 +/- 8.1% for physisorbed substrates. For hippocampal pyramidal neurons to attach and remain in precise micropatterns for weeks in culture, background molecules that remain nonpermissive for extended culture durations need to be identified. Nonpermissive background molecules of either PEG or the amino acid serine (C3H7NO3) were evaluated. The foreground regions were microstamped with PDL. After 29 days in culture the foreground compliance in the PDL regions averaged 86% for serine and 90% for PEG, with only a small decline. The background compliance, or the fraction of square areas in the pattern background which were free of neurite extension, declined from highs of 40% and 55% (midculture) to 5.5% and 12% (29 days) for serine and PEG, respectively. Images of the cultures suggest that PEG is significantly more effective as a nonpermissive substrate. Ellipsometry confirmed long-term maintenance of background chemistry and grafted PEG, with decline in thickness occurring at day 25. In conclusion, these materials, especially PEG, are adequate for the maintenance of long-term patterned cultures of neurons.","abstract_html":"This work describes the development of a technique for high-resolution patterning of proteins or biomolecules on glass substrates for the localization of neurons and their axons and dendrites. The new patterning process uses a microfabricated polydimethylsiloxane (PDMS) stamp with micrometer length features to transfer multiple types of biomolecules to surfaces prepared with (3-aminopropyl)silane (3-APS) or (3-mercaptopropyl)silane (3-MPS) using glutaraldehyde or N-gamma-maleimidobutyryloxysuccinimide ester (sulfo-GMBS) reagents as cross-linkers. PDMS microstamps were used to covalently attach poly-D-lysine (PDL) on glass and silicon dioxide substrates, where polyethylene glycol (PEG) or serine was applied to the background regions. The thickness of each film was measured using ellipsometry and atomic force microscopy (AFM), from which the surface concentrations and grafting density were calculated. Fourier transform infrared spectroscopy was used to examine the structure and organization of the organosilane surfaces. Long-term film stability was evaluated using ellipsometry and static water contact angles. As a biological assay, B104 neuroblastoma cells were plated on microstamped glass coverslips. Results indicated that the stamping and photoresist patterning procedures are equivalent, having an average pattern compliance of 52.6 +/- 4.4% compared to 54.6 +/- 8.1% for physisorbed substrates. For hippocampal pyramidal neurons to attach and remain in precise micropatterns for weeks in culture, background molecules that remain nonpermissive for extended culture durations need to be identified. Nonpermissive background molecules of either PEG or the amino acid serine (C3H7NO3) were evaluated. The foreground regions were microstamped with PDL. After 29 days in culture the foreground compliance in the PDL regions averaged 86% for serine and 90% for PEG, with only a small decline. The background compliance, or the fraction of square areas in the pattern background which were free of neurite extension, declined from highs of 40% and 55% (midculture) to 5.5% and 12% (29 days) for serine and PEG, respectively. Images of the cultures suggest that PEG is significantly more effective as a nonpermissive substrate. Ellipsometry confirmed long-term maintenance of background chemistry and grafted PEG, with decline in thickness occurring at day 25. In conclusion, these materials, especially PEG, are adequate for the maintenance of long-term patterned cultures of neurons.","abstract_has_math":false,"creators":["Branch, Darren Waltz"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biophysics and Computational Biology","degree_department":null,"school":null,"contributors":["Wheeler, Bruce C."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:46:16Z","date_published":"2015-09-25T22:46:16Z","updated_at":"2026-07-22T22:26:25Z","subjects":["Biology, Cell"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9955591"],"render_values":[{"text":"(MiAaPQ)AAI9955591","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/85495","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wheeler, Bruce C."]},{"key":"dc:creator","label":"Author","values":["Branch, Darren Waltz"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:46:16Z","10000-01-01","2000"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biophysics and Computational Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Cell"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/85495","(MiAaPQ)AAI9955591"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This work describes the development of a technique for high-resolution patterning of proteins or biomolecules on glass substrates for the localization of neurons and their axons and dendrites. The new patterning process uses a microfabricated polydimethylsiloxane (PDMS) stamp with micrometer length features to transfer multiple types of biomolecules to surfaces prepared with (3-aminopropyl)silane (3-APS) or (3-mercaptopropyl)silane (3-MPS) using glutaraldehyde or N-gamma-maleimidobutyryloxysuccinimide ester (sulfo-GMBS) reagents as cross-linkers. PDMS microstamps were used to covalently attach poly-D-lysine (PDL) on glass and silicon dioxide substrates, where polyethylene glycol (PEG) or serine was applied to the background regions. The thickness of each film was measured using ellipsometry and atomic force microscopy (AFM), from which the surface concentrations and grafting density were calculated. Fourier transform infrared spectroscopy was used to examine the structure and organization of the organosilane surfaces. Long-term film stability was evaluated using ellipsometry and static water contact angles. As a biological assay, B104 neuroblastoma cells were plated on microstamped glass coverslips. Results indicated that the stamping and photoresist patterning procedures are equivalent, having an average pattern compliance of 52.6 +/- 4.4% compared to 54.6 +/- 8.1% for physisorbed substrates. For hippocampal pyramidal neurons to attach and remain in precise micropatterns for weeks in culture, background molecules that remain nonpermissive for extended culture durations need to be identified. Nonpermissive background molecules of either PEG or the amino acid serine (C3H7NO3) were evaluated. The foreground regions were microstamped with PDL. After 29 days in culture the foreground compliance in the PDL regions averaged 86% for serine and 90% for PEG, with only a small decline. The background compliance, or the fraction of square areas in the pattern background which were free of neurite extension, declined from highs of 40% and 55% (midculture) to 5.5% and 12% (29 days) for serine and PEG, respectively. Images of the cultures suggest that PEG is significantly more effective as a nonpermissive substrate. Ellipsometry confirmed long-term maintenance of background chemistry and grafted PEG, with decline in thickness occurring at day 25. In conclusion, these materials, especially PEG, are adequate for the maintenance of long-term patterned cultures of neurons.","Made available in DSpace on 2015-09-25T22:46:16Z (GMT). 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The new patterning process uses a microfabricated polydimethylsiloxane (PDMS) stamp with micrometer length features to transfer multiple types of biomolecules to surfaces prepared with (3-aminopropyl)silane (3-APS) or (3-mercaptopropyl)silane (3-MPS) using glutaraldehyde or N-gamma-maleimidobutyryloxysuccinimide ester (sulfo-GMBS) reagents as cross-linkers. PDMS microstamps were used to covalently attach poly-D-lysine (PDL) on glass and silicon dioxide substrates, where polyethylene glycol (PEG) or serine was applied to the background regions. The thickness of each film was measured using ellipsometry and atomic force microscopy (AFM), from which the surface concentrations and grafting density were calculated. Fourier transform infrared spectroscopy was used to examine the structure and organization of the organosilane surfaces. Long-term film stability was evaluated using ellipsometry and static water contact angles. As a biological assay, B104 neuroblastoma cells were plated on microstamped glass coverslips. Results indicated that the stamping and photoresist patterning procedures are equivalent, having an average pattern compliance of 52.6 +/- 4.4% compared to 54.6 +/- 8.1% for physisorbed substrates. For hippocampal pyramidal neurons to attach and remain in precise micropatterns for weeks in culture, background molecules that remain nonpermissive for extended culture durations need to be identified. Nonpermissive background molecules of either PEG or the amino acid serine (C3H7NO3) were evaluated. The foreground regions were microstamped with PDL. After 29 days in culture the foreground compliance in the PDL regions averaged 86% for serine and 90% for PEG, with only a small decline. The background compliance, or the fraction of square areas in the pattern background which were free of neurite extension, declined from highs of 40% and 55% (midculture) to 5.5% and 12% (29 days) for serine and PEG, respectively. Images of the cultures suggest that PEG is significantly more effective as a nonpermissive substrate. Ellipsometry confirmed long-term maintenance of background chemistry and grafted PEG, with decline in thickness occurring at day 25. In conclusion, these materials, especially PEG, are adequate for the maintenance of long-term patterned cultures of neurons.","Made available in DSpace on 2015-09-25T22:46:16Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9955591.pdf: 7957000 bytes, checksum: ad8098f7564104ecd36fcbb3776dd1e6 (MD5) Previous issue date: 2000","Embargo set by: Seth Robbins for item 86776 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","146 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000."],"dc:identifier":["http://hdl.handle.net/2142/85495","(MiAaPQ)AAI9955591"],"dc:language":["eng"],"dc:subject":["Biology, Cell"],"dc:title":["Elastomeric Stamping: Design Considerations for Long -Term Maintenance of Neuronal Networks"],"dc:type":["text"],"thesis:degree_discipline":["Biophysics and Computational Biology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:25Z"}